As one of the trainers on Food Network's show Fat Chef, tough-love nutritionist Christine Avanti helps kitchen heavyweights lose the extra pounds they've picked up on the job. Few of us face the endless supply of food that chefs do every day, but we all have to control ourselves now and then, and it isn't easy. We asked Avanti to meet us on the Norwegian Gem, a 2,400-passenger cruise ship, and show us how to handle temptation at an all-you-can-eat-buffet. "I've seen people eat more than 4,000 calories in one sitting at places like this," she says, eyeing the mountains of mashed potatoes and pasta. Her pointers will keep your buffet meals in check, whether you're on the open seas or hitting your local Golden Corral.

Eat everything...but just one bite.

Trying loads of dishes is half the fun of a buffet—and you don't have to give that up. Make a sampler plate and put tiny portions of several items on a salad dish (or the smallest plate you can find). "Do you really need to have more than a teaspoon of something to know how it tastes?" Avanti asks. Not if you like keeping your pants buttoned in public.

Remember it's a meal, not a marathon.

Calories still count when you go back for thirds (or fourths). The key, Avanti says, is thinking of your buffet visit as a normal meal instead of a nonstop grazing session. Choose a lean protein, a complex carbohydrate and some greens that look tempting, or go with the ones that were your favorites on the sampler plate. Then fill your (one and only!) dish with reasonable portions of each.

Be picky.

We're guessing your local buffet isn't known for its award-winning chicken salad or chocolate pudding. You won't get your money's worth by eating run-of-the-mill dishes, so skip them and up the value of your meal by choosing exotic items from the salad bar (our cruise ship had barley salad and marinated mushrooms). They seem indulgent, but they aren't loaded with fat and sugar.

Play with your salad.

No one's making a beeline for the salad bar at a buffet, but you can actually have some fun with it. Create a custom soup, for example: Fill a bowl with mostly broth from whatever non-creamy soup is available, then load it with veggies from the salad bar and finish it off with a lean protein, like some shrimp or chicken. Avanti got this idea from a make-your-own Asian soup station at the buffet we visited.

Watch out for the shiny stuff.

If vegetables look extra glossy, steer clear, even if they're labeled "steamed." Chefs sometimes toss cooked veggies in oil to keep them looking good while they're sitting out, but extra oil means extra fat. The food won't look as inviting, but if it has a dull finish, pile it on!

Drink up.

The more water you drink, the better. "If you don't take in enough water, your body will start to retain it," Avanti explains. That, combined with the fact that restaurant chefs love salt, can lead to a bad case of buffet bloat. "When you're properly hydrated, you'll lose all that excess water weight," Avanti says. A chef on the show tried this tip and lost 11 pounds in one day!

Say no to sugar stand-ins.

It would take super-human resolve to stare down a spread of drippy, gooey desserts and walk away empty-handed. You don't have to skip it—instead, pick a dessert with built-in portion control, like a small cookie or scoop of ice cream. Just don't go for the sugar-free sweets. "I don't do diet foods," Avanti says. "They don't satisfy your body's craving for the real thing."